208 ROYAL SOCIETY OF CANADA 



All examination of the Montreal and Ottawa specimens revealed the 

 fact, that, besides the simple oxeote spicules, three other kinds wei-e 

 present, viz. : protria^nes, anatria^nes and sigraaspires, showing that the 

 sponge was a true tetractinellid and judging from the relative positions 

 of the spicules, probably belonged to the genus Crdniella, 0. S. 



The living form most nearly allied to (\ Lo<jani is probably C. 

 cranium, auct., to which the species under consideration bears a strong 

 resemblance, especially in the size of the spicules. Most of the specimens 

 are spherical in shape and remains are abundant of what was evidently 

 the basal anchoring tuft. 



The spicules are as enumerated below : — 



(a) Megasclera ; (1) Somal oxea, frequently anisoactinate but often 

 filiform at either end and sometimes with the ends equally but only 

 moderately attenuated ; maximum size 56 by 054 mm. (Plate III., tig. 

 8a) ; these spicules radiate from the centre or from a point near the 

 centre to the surface. (2) Cortical oxea, rather obtusely but sharply 

 pointed, smooth and slightK' bent, from 0-63 to 1"22 mm. long and with 

 a maximum thickness of 0-02 mm. (Plate III., fig. 8^} ; confined to the 

 cortex and disposed radiately. (3) Protria-nes, reaching a length (broken) 

 of -4*T3 mm. ; cladi from 0041 to 0111 mm. long, chord from 0*044 to 

 0-085 mm., maximum thickness of rhabdome 0-013 mm. (Plate III., figs. 

 8e, 8c/) ; immature forms of this spicule are abundant (Plate III., figs. 8^^, 

 ^f). (4) Anatiia-nes, measured up to 438 mm. in length (broken) ; cladi 

 from 0178 to 0-274 mm. long, chord from 0'095 to 0205 mm., average 

 thickness of rhabdome 0013 mm. (Plate III., fig. 8(7) ; immature forms 

 occur with cladi 0-041 mm. long and with very slender rhabdomes about 

 000(i mm. thick (Plate 111., tig. 8A). The cladi of the anatriœnes are 

 remarkable for their great length. (6) 3Hcrosclera. ; (4) sigmaspires, 

 minutely spined ; average length 0019 mm. (Plate HI., fig. 8i). 



Localities. — ^lontreal, a number of specimens. Sir William Dawson ; 

 Ottawa, at Odell's brick-yard, several specimens, H. M. Ami, 1888, 1889. 



In 1873 Mr. Whiteaves collected a few spicules, belonging to hexac- 

 tinellid sponges, in the Leda clay at the '• nien " brick works, Montreal. 



These spicules are as follows : 



1. Heavily barbed, anchor-like sjiicules with expanded ends having 

 from five to seven stout teeth (Plate III., figs. 0, \hi, \)b, 9c) ; a broken 

 spicule of this kind measured as much as 4-9 mm. in length. 



1. A smooth, slender hexact with four short rays in one plane and 

 two long rays at right angles to tlie other four (Plate III., fig. 9c/). 



3. Smooth pentacts Avith short, stout, sharply pointed rays varying 

 in length from 0-232 to OSOti mm. and with a thickness at the base of 

 from 0-0G8 to 0-041 mm. (Plate II J., Hgs. 9cj, 9/). 



4. A small portion of the framework of a sponge probably of the 

 suborder Victyonina, Zittel (Plate III., fig. 9c/). 



